Endoscopes have been used for many years in the medical field to look within a selected region of a patient's body or to perform surgical, therapeutic, diagnostic, or other medical procedures under direct visualization. A conventional endoscope generally contains several components including illuminating means such as light-emitting diodes or fiber optic light guides connected to a proximal source of light, an imaging means such as a miniature video camera or a fiber optic image guide, and a working channel. These components are positioned within an endoscope sheathing tube. Flexible or steerable endoscopes also incorporate an elongated flexible shaft and an articulating distal tip to facilitate navigation through the internal curvature of a body cavity or channel.
Colonoscopy is a medical procedure in which a flexible endoscope, or colonoscope, is inserted into a patient's colon for diagnostic examination and/or surgical treatment of the colon. A standard colonoscope is typically 135-185 cm in length and 12-13 mm in diameter. Colonoscopes generally include a fiber optic imaging bundle, illumination fibers, one or two instrument channels that may also be used for insufflation or irrigation, and a suction channel that extends the length of the colonoscope to facilitate removal of occlusions such as mucus, plaque, fecal matter, or other material that can obstruct the physician's view or interfere with the endoscopic procedure. The colonoscope is inserted via the patient's anus and is advanced through the colon, allowing direct visual examination of the colon, the ileocecal valve, and portions of the terminal ileum. Approximately six million colonoscopies are performed each year.
In order to examine a patient's anatomy during a colonoscopy, it is essential to have a clear field of view. Currently, about 20% of colon polyps are undetected due to low visibility, which can arise from inadequate lens cleaning. Poor colon preparation is also a cause of reduced visibility in the colon. Presently, about 10% of all patients are non-compliant with preparatory procedures and approximately 4% of all patients are unable to complete the exam due to an excess of stool in the colon. The remaining 6% of all cases are considered marginal, and the colonoscopy may still be performed if the colon is evacuated as a part of the procedure. Conventionally, the colons of marginal cases are cleared by repeatedly administering several small (60 cc) fluid flushes through an endoscope's working channel by means of an ancillary apparatus that employs a low-volume wash and suction. The waste is then removed through the suction channel in the endoscope. However, this tedious and inefficient process is limited by the amount of stool that can be removed with each flush. The process also causes a loss of productivity due to the added time required to evacuate the colon. Therefore, there is a need for a system and method of efficiently cleaning poorly prepared colons.
One example of a colon irrigation method for colonoscopy is described in U.S. Pat. No. 5,279,542, entitled “Colon Irrigation Method.” The '542 patent describes an irrigation instrument for use in evacuating the colon prior to endoscopic surgery. The instrument consists of an elongate tube with a plurality of longitudinally and circumferentially spaced apertures along its entire length. A pressurized source of irrigation fluid is connected to the tube for feeding fluid through the channel and out through the apertures with an essentially uniform radial distribution. The tube is thin enough to fit down the biopsy channel of an endoscope. The invention essentially provides an improved method for providing irrigating fluid to a distal end of an endoscope or to a surgical site.
Although the apparatus and method of the colon irrigation method described in the '542 patent provides a means of irrigation for colonoscopy and other endoscopic procedures, the device is an accessory to standard endoscopes that uses the working channel of the endoscope. As such, the apparatus requires labor-intensive assembly on an as-needed basis. Furthermore, it is up to the physician to determine the amount of cleaning that is required and to control the apparatus such that the patient is sufficiently prepped for an examination. This reduces the time that the physician has to perform the actual examination.
Given these problems, there is a need for a system that can automatically prepare poorly prepped patients for an endoscopic examination with minimal physician supervision. In addition, the system should operate based on the patient's individual physical anatomy and detected level of cleanliness so that a desired field of view is created in which an examination is conducted.